Improvement in baths for tempering articles of iron and steel



UNITED STATES PATENT OFFICE.

HENRI HERRENSOHMIDT, OF MELBOURNE, VICTORIA.

IMPROVEMENT IN BATHS FOR TEMPERING ARTICLES OF IRON AND STEEL.

Specification forming part of Letters Patent No. 183,804, dated October31, 1876; application filed April 7, 1876.

To all whom it may concern Be it known that I, HENRI HERREN- SCHMIDT, ofMelbourne, in the British Colony of Victoria, civil engineer, haveinvented a certain Bath for Tempering Articles of Iron and Steel, to beused instead of water in the process of tempering, of which thefollowing is a specification:

My bath is made by mixing together one hundred parts of muriatic acid,twenty-four parts of nitric acid, and fourteen parts of sulphate ofzinc, and soaking therein for twentyfour hours some pieces of cast-iron,white metal preferred. The undecomposed portion of the cast-iron is thenremoved, and the mixture diluted with one thousand parts of cold water,when it is ready for use. All the parts are by weight.

In using my bath it is to be treated in the same Way as if it were waterin which the heated steel is to be tempered. If, however, the steel isnot co'mpact,it must first be welded. When the bath begins to boil fromrepeated use, it must be allowed to cool, as it should not be used abovethe boiling-point. It may be kept in an open vessel, as it does not loseits eflicacy by exposure to the atmosphere.

Steel of every quality may be refined and improved by my bath; but itseffect is more obvious in inferior kinds, and that not only on thesurface, but throughout the whole body of the metal. It is particularlyapplicable to tools; but large masses of metal may be refined andimproved by it, if immersed for a sufficient time.

I claim as my invention The bath for tempering iron and steel articles,which consists of. muriatic and nitric acids, sulphate of zinc, iron,and water, prepared substautially in the manner and proportions hereinspecified.

H. HERRENSUHMIDT. Witnesses:

EDWARD WATERS, W. S. BAYSTON.

